How to create a dithering effect?
For Eevee, the principle is similar to the one used in this answer.

Simply you can change the input parameters and play with the Voronoi texture options.



I've changed few things to the node setting.



Voronoi input is set to camera texture coordinates.

Voronoi changed to 2D and distance to edge.

Colors inverted.

Inputs on the right tuned.